Abstract: LED driver apparatus and methods may include a sensing circuit for adjusting an output based on either a pulse width modulation dimming control or an analog dimming control. An LED driver apparatus and methods may also include a sensor for a parameter such as temperature and for recording such parameter, for example as a function of time. A setting unit for an LED driver apparatus can be used to sense and/or adjust settings in the LED apparatus even when the LED apparatus is not independently powered.

Abstract: LED driver apparatus and methods may include a sensing circuit for adjusting an output based on either a pulse width modulation dimming control or an analog dimming control. An LED driver apparatus and methods may also include a sensor for a parameter such as temperature and for recording such parameter, for example as a function of time. A setting unit for an LED driver apparatus can be used to sense and/or adjust settings in the LED apparatus even when the LED apparatus is not independently powered.

Abstract: An LED-based luminaire is configured to direct light from an LED source downwardly. However, a portion of the luminaire intentionally reflects part of the light upwardly toward a ceiling of a structure. A control circuit of an LED-based luminaire enables the luminaire to be dimmed by an off-the-shelf dimmer. The control circuit also determines when a temperature of the LED-based luminaire exceeds a desired temperature range, and employs a feedback circuit to reduce power delivery to the LEDs until the temperature is again within the desired temperature range.

Abstract: An LED-based light engine has a circuit board upon which at least one LED circuit is mounted. A power driver is also mounted on the circuit board. The power driver accepts an AC input power and outputs a DC output power that powers the LED circuit. The circuit board is divided into an LED zone and a driver zone, which are thermally insulated relative to one another so that heat does not flow between the LED and driver zones. Slots are formed through the circuit board between the LED zone and driver zone to further block heat flow between the LED and driver zones.

Abstract: An LED-based luminaire is configured to direct light from an LED source downwardly. However, a portion of the luminaire intentially reflects part of the light upwardly toward a ceiling of a structure. A control circuit of an LED-based luminaire enables the luminaire to be dimmed by an off-the-shelf dimmer. The control circuit also determines when a temperature of the LED-based luminaire exceeds a desired temperature range, and employs a feedback circuit to reduce power delivery to the LEDs until the temperature is again within the desired temperature range.

Abstract: An arc lamp lightsource module comprises a removable lamp unit including an arc lamp attached to two radial electrode heatsinks that are in turn disposed in an insulating sleeve housing. A chassis has a catch and a clip to lock down the removable lamp unit. An igniter is included to power the arc lamp. A single fan and an air plenum are disposed in the chassis and provide for a cooling airflow that is split between the igniter and the two radial electrode heatsinks. A pair of machine screws provide electrical contact to each of the two radial electrode heatsinks and that have crowned heads for a smooth contact surface. A printed circuit board (PCB) has springboard cutouts and electrical pads providing for a spring-pressure electrical contact between the igniter and the arc lamp through the pair of machine screws.

Abstract: A blue-light polymerizing system comprises a xenon arc lamp in which its sapphire window includes a blue-bandpass filter coating. This eliminates any external color filters that would otherwise be necessary for the polymerization of dental composite materials in a patient's mouth. The blue-bandpass filter coating causes the xenon arc lamp to heat an extra 10° C. higher than would otherwise be the case. So a special anode heatsink is fitted in which the front and back halves of each radial fin have been separated, and one of these groups of separated fins has been tilted off normal. Such changes the otherwise laminar airflow through the anode heatsink fins to a turbulent flow that is better able to collect heat and carry it off.

Abstract: A method and apparatus for imaging a substrate (such as silicon or silicon dioxide) beneath and between a dense array of strips (such as photoresist strips composed of dielectric or other material) using a polarizing optical microscope. In preferred embodiments, the apparatus of the invention includes a polarizer for polarizing optical illuminating radiation, an analyzer for receiving polarized radiation reflected from the sample, and a variable retarder whose retardation characteristic can be controlled to enhance the light signal transmitted through the analyzer from the substrate in a region of interest of the sample. The variable retarder can be a fixedly mounted retarder whose birefringence is variable in response to a control signal, or a rotatably mounted retarder plate having fixed birefringence which is mechanically rotatable to control the orientation of its optical axis.